1. Field of the Invention
The present invention relates to a manufacturing method of an electrode material.
2. Description of the Related Art
The field of portable electronic devices such as personal computers and cellular phones has progressed significantly. The portable electronic devices need a rechargeable power storage device that is small, light-weight, and reliable, which has a high energy density. As such a power storage device, a lithium ion secondary battery is known, for example. Also, development of electronically propelled vehicles on which a secondary battery is mounted has also been progressing rapidly due to growing awareness of environmental problems and energy problems.
In a lithium ion-secondary battery, the following and the like have been known as a positive electrode active material (see Patent Document 1, Non-Patent Document 1, and Non-Patent Document 2): a phosphate compound with an olivine structure containing lithium (Li) and iron (Fe), manganese (Mn), cobalt (Co), or nickel (Ni), such as lithium iron phosphate (LiFePO4), lithium manganese phosphate (LiMnPO4), lithium cobalt phosphate (LiCoPO4), lithium nickel phosphate (LiNiPO4), and the like.
Lithium iron phosphate is represented by the composition formula LiFePO4, and FePO4 which is obtained by taking lithium from LiFePO4 is also stable; consequently, capacitance of a power storage device that is manufactured using the above material can be increased safely.